1. Field of the Invention
The present invention relates to a method for optimizing the scanning process of a mobile terminal, the scanning process being performed by the mobile terminal in order to discover an available network to which a connection is possible, wherein at least a part of existing networks is registered to a server, wherein said server provides its information regarding the registered networks to the mobile terminal.
2. Description of the Related Art
In recent years several types of wireless communication systems have been developed. For example, wireless local area networks (WLAN) are widely spread nowadays, cellular networks, such as Universal Mobile Telecommunication Systems (UMTS), have gained paramount importance, and, most recently, WiMAX (defined as Worldwide Interoperability for Microwave Access) has been developed as a standard-based technology enabling the delivery of last mile wireless broadband access. Each of these systems provides different types of services and specific applications.
According to the existing different types of wireless communication systems, mobile terminals nowadays support multiple network interfaces, with WiFi, UMTS, GSM and Bluetooth already available in the market. While connection to the GSM/UMTS network is neatly arranged by network operators, other networks, such as WiFi and Bluetooth, require continuous scanning of the mobile terminal to guarantee a reasonable percentage of connection time. In order to discover available networks, the terminal needs to perform a technology-specific scan function. In general, this results in such intensive battery consumption, that the mobile terminals functionality is drained at unacceptable rates.
In the case of networks where the terminal receives advertisements (for instance, beacons), such as in WiFi, the scanning time may be considered as the period in which the wireless card is listening on the radio link and can receive such advertisements. During the rest of the time, the device is considered as non listening. When a protocol does not provide any advertisements, such as Bluetooth Inquiry or WiFi active Probe Request modes, a scan is considered as the initiation of the scanning process.
Certain strategies have been developed, such as the MIH (Media Independent Handover), which communicate available networks within a given area to mobile terminals. Consequently, the terminal does not have to perform a scanning process, but can directly attempt to connect to the known networks in its vicinity. However, devices that are not MIH-enabled need to periodically scan for available networks, resulting in rapid battery consumption as mentioned above. MIH-enabled devices, on the other hand, can save battery and scanning time when using the information regarding available networks provided by the MIH service. In the context of the MIH service, this information is usually provided by an information server (IS) to which existing networks are registered.
However, there will always be situations in which mobile devices can not use the information provided by the information server, either because the information is incomplete or outdated. This may be due to the fact that networks that do exist have not been registered yet in the IS. In such cases, the terminal is reduced to non-MIH functionality, which typically involves periodical scans according to the policies implemented in the terminal. Such a situation can be described as a non-MIH operation of MIH-enabled devices, in which terminals act as they were not MIH-enabled, i.e. they have to periodically scan in order to discover available networks to which connection is possible.